The chromosomal aneuploidy in oocytes is one of main causes of abortion and neonatal birth defects.It is mainly due to the premature separation of sister chromatid caused by the loss of Cohesin protein complex and the non-disjunction sister chromatids caused by abnormal microtubule dynamics aneuploidy.As a pathway of protein post-translational modification,SUMO modification(or SUMOylation)involves many physiological regulation processes including cell proliferation,differentiation,apoptosis,and cycle regulation.In the oocytes,SUMOylation can regulate the localization of Cohesin protein complex on the chromosome to affect the chromosomal aneuploidy in oocytes caused by premature separation of sister chromatid.On the other hand,SUMOylation can regulate the microtubule dynamics to affect the chromosomal aneuploidy in oocytes caused by non-disjunction sister chromatids.Therefore,SUMOylation plays an important role in regulating the chromosomal aneuploidy of oocytes;the exact mechanisms via which the SUMOylated substrates affect aneuploidy in oocytes remain unclear.This articles reviews the roles of SUMOylation in premature separation and non-isolated chromatid aneuploidy in oocyte from the effects of SUMOylationon Cohesin protein complex and microtubule dynamics.
Aneuploidy ; Cell Cycle Proteins ; Chromatids ; Chromosomal Proteins, Non-Histone ; Chromosome Segregation ; Humans ; Microtubules ; Oocytes ; cytology ; Sumoylation

Adult ; Chromatids/genetics* ; Chromosome Aberrations ; Humans ; Infertility, Male/genetics* ; Male ; Meiosis ; Metaphase/genetics* ; Spermatocytes/physiology*

INTRODUCTION: Chromosomal mutations are casual events in neoplasia development. Biomarker cytogenetic assays can determine exposure to mutagenic agents in occupational settings. This study assessed early biological marker chromosomal aberrations among health workers in the chemotheraphy oncology wards/ clinics, exploring its association to the subjects' occupational, environmental and baseline profile.
METHODS: This was an IRB approved cross-sectional exploratory study among hospital personnel working in the chemotherapy oncology facility of a tertiary government hospital, who underwent structured interview and blood extraction for cytogenetic assay after informed consent. Study funds only permitted assay of 44 specimens of 144 planned sample size, hence, Stata 6.0 only analyzed data from 44 subjects.
RESULTS: All 44 subjects had varying exposure to chemotherapy drug infusions. Of these, 79% had 1.0 breaks per cell (hypersensitive). Predominantly chromatid breaks (CTB), chromatid gaps (CTG), sister chromatid exhanges (SCE) were seen. No significant association was shown between mutagenic sensitivity and baseline characteristics, but with small sample size.
CONCLUSION: 21% borderline to hypersensitive mutagenic sensitivity among oncology workers at the tertiary government hospital is relatively significant, despite small sample size, connoting a must preventive promotive practice of chemotherapy administration in the workplace.

Human ; Male ; Female ; Chromosome Aberrations ; Chromosomes ; Drug Therapy ; Personnel, Hospital ; Cytogenetics ; Chromatids ; Mutagens

Chemotherapy agents can induce chromosomal instability, including a variety of chromatid or chromosomal aberrations. However, only limited data is available on the effect of chemotherapy on the kinetics of chromosomal instability in peripheral blood lymphocytes. Here, we report the case of an ovarian cancer patient who showed chromosomal instability in peripheral blood lymphocytes while undergoing chemotherapy. Karyotypic analysis of peripheral blood 1 day after administration of cisplatin and etoposide showed chromosomal or chromatid aberrations, including gaps, breaks, and fragmentation. Chromosome study after completion of the first chemotherapy cycle showed normal karyotype. This finding suggests that chemotherapeutic agents can induce transient chromosomal instability in peripheral blood lymphocytes.
Chromatids ; Chromosomal Instability ; Chromosome Aberrations ; Cisplatin ; Etoposide ; Humans ; Karyotype ; Kinetics ; Lymphocytes ; Ovarian Neoplasms

Structural abnormalities of the Y chromosome affect normal testicular differentiation and spermatogenesis. The present case showed a rare monocentric derivative Y chromosome with partial duplication of Yp including the SRY gene and deletion of Yq12 heterochromatin. The karyotype was 46,X,der(Y) (pter-->q11.23::p11.2-->pter).ish der(Y)(DYZ3+,DYZ1-,SRY++), confirmed through a FISH study. Even though the patient possessed an abnormal Y chromosome, testicular biopsy showed normal testicular volumes in the proband, with gonadal hormonal levels in the normal range but bilateral varicocele and hypospermatogenesis. We speculate that the abnormal Y chromosome arose from sister chromatids during Y chromosome recombination or intra chromosomal NAHR (non-allelic homologous recombination) during meiosis in the patient's father or in the very early stages of embryogenesis. The derivative Y chromosome might interfere in the meiotic stage of spermatogenesis, leading to the developmental arrest of germ cells. The present case illustrates that the infertility phenotype can have various causes. Also, it emphasizes the importance of accurate and various genetic analyses and could aid in male infertility treatment.
Azoospermia ; Biopsy ; Chromatids ; Embryonic Development ; Fathers ; Female ; Genes, sry ; Germ Cells ; Gonads ; Heterochromatin ; Humans ; Infertility ; Infertility, Male ; Karyotype ; Male ; Meiosis ; Oligospermia ; Phenotype ; Pregnancy ; Recombination, Genetic ; Reference Values ; Siblings ; Spermatogenesis ; Varicocele ; Y Chromosome

DNA double-strand breaks (DSBs) occur commonly in the all living and in cycling cells. They constitute one of the most severe form of DNA damage, because they affect both strand of DNA. DSBs result in cell death or a genetic alterations including deletion, loss of heterozygosity, translocation, and chromosome loss. DSBs arise from endogenous sources like metabolic products and reactive oxygen, and also exogenous factors like ionizing radiation. Defective DNA DSBs can lead to toxicity and large scale sequence rearrangement that can cause cancer and promote premature aging. There are two major pathways for their repair: homologous recombination(HR) and non-homologous end-joining(NHEJ). The HR pathway is a known "error-free" repair mechanism, in which a homologous sister chromatid serves as a template. NHEJ, on the other hand, is a "error-prone" pathway, in which the two termini of the broken DNA molecule are used to form compatible ends that are directly ligated. This review aims to provide a fundamental understanding of how HR and NHEJ pathways operate, cause genome instability, and what kind of genes during the pathways are associated with head and neck cancer.
Aging, Premature ; Cell Death ; Chromatids ; DNA ; DNA Damage ; Genomic Instability ; Hand ; Head ; Head and Neck Neoplasms ; Humans ; Loss of Heterozygosity ; Oxygen ; Radiation, Ionizing ; Siblings

DNA double-strand breaks (DSBs) occur commonly in the all living and in cycling cells. They constitute one of the most severe form of DNA damage, because they affect both strand of DNA. DSBs result in cell death or a genetic alterations including deletion, loss of heterozygosity, translocation, and chromosome loss. DSBs arise from endogenous sources like metabolic products and reactive oxygen, and also exogenous factors like ionizing radiation. Defective DNA DSBs can lead to toxicity and large scale sequence rearrangement that can cause cancer and promote premature aging. There are two major pathways for their repair: homologous recombination(HR) and non-homologous end-joining(NHEJ). The HR pathway is a known "error-free" repair mechanism, in which a homologous sister chromatid serves as a template. NHEJ, on the other hand, is a "error-prone" pathway, in which the two termini of the broken DNA molecule are used to form compatible ends that are directly ligated. This review aims to provide a fundamental understanding of how HR and NHEJ pathways operate, cause genome instability, and what kind of genes during the pathways are associated with head and neck cancer.
Aging, Premature ; Cell Death ; Chromatids ; DNA ; DNA Damage ; Genomic Instability ; Hand ; Head ; Head and Neck Neoplasms ; Humans ; Loss of Heterozygosity ; Oxygen ; Radiation, Ionizing ; Siblings

The aim of this study is to identify hRad21-binding sites in human chromosome, the core component of cohesin complex that held sister chromatids together. After chromatin immunoprecipitation with an hRad21 antibody, it was cloned the recovered DNA and sequenced 30 independent clones. Among them, 20 clones (67%) contained repetitive elements including short interspersed transposable elements (SINE or Alu elements), long terminal repeat (LTR) and long interspersed transposable elements (LINE), fourteen of these twenty (70%) repeats clones had Alu elements, which could be categorized as the old and the young Alu Subfamily, eleven of the fourteen (73%) Alu elements belonged to the old Alu Subfamily, and only three Alu elements were categorized as young Alu subfamily. There is no CpG island within these selected clones. Association of hRad21 with Alu was confirmed by chromatin immunoprecipitation-PCR using conserved Alu primers. The primers were designed in the flanking region of Alu, and the specific Alu element was shown in the selected clone. From these experiments, it was demonstrated that hRad21 could bind to SINE, LTRs, and LINE as well as Alu.
Alu Elements ; Chromatids ; Chromatin ; Chromatin Immunoprecipitation ; Chromosomes, Human* ; Clone Cells ; CpG Islands ; DNA ; DNA Transposable Elements ; Humans ; Humans* ; Siblings ; Terminal Repeat Sequences

BACKGROUND: The anaphase promoting complex (APC) promotes the degradation of mitotic cyclins as well as other substrates involved in sister chromatid adhesion. This study was carried out to examine the relationship between the APC expression and the clinicopathological variables, in an attempt to determine the role of the APC in the proliferation of lung cancer and to evaluate the possibility of an aberrant APC function in surgically resected squamous cell carcinomas and adenocarcinomas of the lung. METHODS: Immunohistochemical staining was performed for APC, Ki-67, cyclin B1, Cdc2, MMP-2 and VEGF in 55 cases of squamous cell carcinoma and 34 cases of adenocarcinoma of the lung, using the avidin-biotin-peroxidase method. RESULTS: The immunohistochemical stains for APC revealed a positive reaction in 49 cases (55.1%). The APC expression level was higher in the cyclin B1-positive group (p= 0.01), the Cdc2-positive group (p=0.001), the MMP-2-positive group (p=0.03), the group with lymph node metastasis (61.4% vs 48.9%), and the group with stage II/III cancer (60.7%) compared with those with stage I (42.9%). CONCLUSIONS: The APC may have an aberrant function, such as a change in its role in controlling the cell cycle, and might be associated with the invasiveness and proliferation of tumor cells.
Adenocarcinoma* ; Anaphase* ; Anaphase-Promoting Complex-Cyclosome* ; Carcinoma, Squamous Cell* ; Cell Cycle ; Chromatids ; Coloring Agents ; Cyclin B1 ; Cyclins ; Humans ; Lung Neoplasms ; Lung* ; Lymph Nodes ; Neoplasm Metastasis ; Siblings ; Vascular Endothelial Growth Factor A

OBJECTIVETo study the impact of postovulatory ageing to balanced predivision of oocyte sister chromatid.

METHODSThe mouse oocytes were cultured 0-72 h. Then chromosome 16 was detected by fluorescence in situ hybridization (FISH). The oocyte spindle and chromosome configuration were examined by immunocytochemistry.

RESULTSFor freshly ovulated mouse oocyte, the balanced predivision of sister chromatid occurred only at 7%. However, for oocytes cultured for 24 h, 48 h and 72 h in vitro, the balanced predivision of sister chromatid occurred up to at 32%, 51% or 62% respectively (P< 0.01). The abnormal cell spindle and chromosome configuration occurred at 9% of freshly ovulated oocytes, but it increased to 63%, 83% and 98% when the oocytes were cultured in vitro for 24 h, 48 h or 72 h respectively (P< 0.01).

CONCLUSIONThe occurrence of balanced predivision of oocyte sister chromatid may result during postovulatory ageing, and may be related to change of oocyte spindle and chromosome configuration.

Aging ; physiology ; Animals ; Cells, Cultured ; Chromatids ; genetics ; Chromosomes, Mammalian ; genetics ; Female ; Immunohistochemistry ; In Situ Hybridization ; Mice ; Oocytes ; cytology ; metabolism